mapreduce - Hadoop rack awareness configuration -

mapreduce - Hadoop rack awareness configuration -

i'm using hadoop , need configure rack awareness, can 1 give me thought or tutorial how works?

i'm using hadoop 1.2.1.

thank's lot

rack topology, in context of hadoop, defines how machines physically located in rack in info center. combined traditional network design , top of rack switching, allows infer how close machines 1 another, logically, in terms of network connectivity. physical locality of machines has bearing on other concerns such powerfulness infrastructure, critical understanding possible fault domains in system.

rack topology configured in hadoop implementing script that, when given list of hostnames or ip addresses on command line, prints rack in machine located, in order. implementation of topology script exclusively administrator , may simple shell script has hardcoded list of machines , rack names, or sophisticated c executable reads info relational database. 1 of mutual types of scripts 1 uses csv file of machine rack mappings.

here 1 illustration of it

http://wiki.apache.org/hadoop/topology_rack_awareness_scripts

hadoop mapreduce